Ward Upham: Extension Blog Contributor
Extension Associate – Home Horticulture Rapid Response Coordinator
& Extension Master Gardener Coordinator
Kansas State University Extension
wupham@ksu.edu
Apple trees that are not pruned for several years will often produce so many branches that very little energy is left for fruit production. Overgrown apple trees are also difficult to harvest and spray. Gardeners who have such a tree are often at a loss as to how to get it back in shape.
Often the best (tongue-in-cheek) recommendation s for such a tree is to make one pruning cut at ground level and start over with a new tree. However, trees may have sentimental value that will make revitalization worth the time and effort. Realize that this will be a multi-year process because no more than 30 percent of the tree should be removed in one year. Here are some steps to follow:
- Remove all dead wood. This does not count toward the 30 percent.
- Remove suckers from the base of the tree.
- Choose approximately six of the best branches to keep as scaffold branches. Remove all others. Branches should be cut flush to the branch collar. The collar is that natural swelling that occurs where a branch connects to the trunk or to a larger branch. Removing the collar would leave a larger wound that would take additional time to heal. Do not paint wounds. Research has shown that wounds heal more quickly if left open. Candidates for removal include branches with narrow crotch angles, which are more likely to break in wind and ice storms, and those that cross branches you will save. This may be all that is possible the first year if the 30 percent threshold has been reached.
- Thin the branches on each scaffold branch. Remove crowded branches to open up the tree to light and allow humidity to escape. Shorten each scaffold branch by cutting back to a side branch. When you are through, the tree should have enough wood removed so that a softball can be thrown through the tree.
Severe pruning often will cause an apple to tree to produce vigorous side shoots from the trunk, called water sprouts. Main branches will also produce suckers that grow straight up. The suckers and water sprouts should be removed throughout the growing season so the center of the tree stays open.
In the case where a tree cannot be saved but you would like to preserve the apple tree variety, consider grafting. Scions taken from the old tree can be grafted onto a new rootstock to form a new tree. If you are not able to do so yourself, contact a local fruit tree nursery to find someone who may be able to help.
To anyone serious about tree pruning, I would strongly recommend reading Alex Shigo’s Tree Pruning or A New Tree Biology. He makes in-depth recommendations for pruning based on his years of research into the healing of trees after injury and pruning, and explains and shows why the location of pruning cuts is so important. His basic premise is that trees compartmentalize damaged wood and infections (he writes, “humans heal, trees compartmentalize”). When making pruning cuts, it’s important to preserve the “protection zone” (the point at which the tree is most able to produce compounds to suppress the growth of fungus and bacteria) at the base of the branch. Flush cuts, that is cuts that take away any of the branch collar, remove part or all of the protection zone and leave the tree open to infection. The radical pruning that’s necessary for an old apple tree, will involve so many cuts that working with the tree’s ability to compartmentalize infection will be extremely important.
One other thing, relevant to that part of the country: these orchard pruning techniques do NOT work on all trees. It is common in places like Wenatchee and Yakima to see shade and ornamental trees pruned like orchard trees, as orchard workers look to make a few extra dollars. These people ruin the shade and ornamental trees in the area when they go out and prune everything into an orchard tree.
Why 30%?
I believe it could be taken as up to 30% and/or no more than 30%. The reason is what was mentioned about water sprouts[my term], which are vigorous vertical growing branches which produce excessive foliage growth but no fruit. Pruning is definitely an art.
Over 30% and the tree is overly stressed.
Quote:
“Apple trees that are not pruned for several years will often produce so many branches that very little energy is left for fruit production.”
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It’s interesting that while on many mountain hiking trips over the decades, I’ve run across many apple trees from old long abandoned homesteads which hadn’t been pruned in many decades. Their production was always fine, even without irrigation. I had to assume they were tapped into the surrounding chaparral and wild trees through the underground mycorrhizal grid. In the old days of course they would have been mostly the standard trees. But they always produce and I’ve wondered maybe if some pruning does take place accidentally when the bears came around and broke off small branches and twigs as they gleaned for apples.
There was an interesting article last fall 2014 about the wild apple forests of Kazakhstan. Clealy no pruning there, but one wonders how it does really work in the wild. I have to admit, this is one destination place I have wanted to visit because of the Apple forests.
http://www.theguardian.com/lifeandstyle/2014/nov/08/kazakhstan-wild-apples-endangered-alys-fowler
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I have a question about sealants. If one is topworking a tree and adding bark grafts should one seal the entire cut surface, only around the grafts, or not at all and hope the wrapping is sufficient? Presumably with a cleft graft one would still want to at least cover the split with something.
I seriously need one to cut my trees at the backyard. Great job, Thank you for doing the effort of coalescing these. The tips you shared sounds easy and beginner-friendly. I’d definitely try these for my very own use. Keep up the good work.
Great post and tips! I often hire one to prune and trim some apple trees in my garden, tree pruning is really quite complicated and tedious especially if we aren’t familiar with such work. But it would definitely save us much time to hire a professional arborist to do the job.